Revegetation projects open opportunities for nurseries, seed companies

By LEE FARREN
For the Capital Press

Growers of native plants and seeds have found an expanding market in government roadside revegetation projects.

In 2007 U.S. Forest Service botanist Scott Riley co-wrote a paper outlining the opportunities for native plant growers created by new federal policies for forest highways in the Pacific Northwest.

"Overall, there's a general move toward native plants for city, county, state and federal land. It's still a fairly new concept with land management agencies, so we have a lot of education to do," Riley said.

Roadside revegetation projects often cover large areas and require large amounts of seed and seedlings of grasses, forbs, shrubs and trees. Typically, the road-building agency specifies the type and number of plants for each site. The road-building contractors then purchase the required material from native plant nurseries and seed companies.

"We probably use hundreds of thousands of native plants each year. We've had projects that used 40,000 just on one roadside," said Sandy Salisbury, a landscape architect for the Washington State Department of Transportation. With projects all over the state, WSDOT uses everything from sagebrush and rabbit brush to Douglas fir and Western red cedar. Because roadside maintenance involves herbicides, grasses and resistant woody species are in high demand.

Agencies look for genetic diversity and the ability to survive under harsh conditions. Roadside plantings are often on slopes exposed to the sun, with little organic matter.

"We'd love it if growers could collect seeds and cuttings from comparably harsh sites. Things that survive on exposed rocky sites do well," Salisbury said.

She isn't interested in pretty flowers, super top growth or uniformity, she said. What she does want is strong, healthy root systems, preferably inoculated with native mycorrhizae.

Road-building agencies are developing new methods for seeding and planting natives. Hydroseeding is now used for also for forbs, shrubs and trees as well as grasses. Erosion mats are seeded with native species and placed on steep sites. Seedlings can be planted in inaccessible areas with an expandable stinger that attaches to an excavator.

As part of their road-building projects, federal and state agencies also plant mitigation sites with natives.

"Mitigation is when we did some construction and destroyed a wetland, say, so we replace that function. We either purchase property or find a place on the right of way to restore to wetland status," said Will Lackey, vegetation coordinator manager for the Oregon Department of Transportation. Lackey said ODOT uses 70 to 80 percent native plants in construction outside of urban areas.

Among their other benefits, native plants help defend against invasive species and improve soil and water quality.

"We use native plants because they are adapted to the conditions we're trying to grow them in, and they fit the context of the areas where we are putting them. Because they are local, they give a character to the place, and they tend not to be invasive," Salisbury said.

She expects native plants to reproduce and spread, so that eventually the site and the plants adapt to each other. The aim is to create a natural self-sustaining system.

Online

PlantNative maintains a comprehensive website with nationwide listings of native plant nurseries and regional plant lists, a directory of community service and landscape professionals committed to using native plants, a how-to tutorial and books on native plants at www.plantnative.org.

More information about the use of native plants for roadside revegetation:

* www.fs.fed.us/wildflowers/nativeplantmaterials/using.shtml

* www.nativerevegetation.org/

* "Roadside Revegetation: A New Frontier for Native Plant Growers," by Scott A. Riley and Kim M. Wilkinson -- www.fs.fed.us/rm/pubs/rmrs_p050/rmrs_p050_072_076.pdf

* "Roadside Revegetation: An Integrated Approach To Establishing Native Plants" -- www.wfl.fhwa.dot.gov/td/publications/revegetation.htm